Tobacco



United States Patent 3,372,700 TOBACCO Joseph N. Schumacher, Donald L. Roberts, and Wilmer A. Rohde, Winston-dalem, N.C., assignors to R. J. Reynolds Tobacco Company, Winston-Salem, N.C., a corporation of New Jersey No Drawing. Filed Aug. 2, 1965, Ser. No. 476,709 Claims. {CL 131-17) This invention relates to a tobacco product and has for an object the provision of a composition and process for improving the flavor :and aroma of tobacco and tobacco smoke.

It is well known in the tobacco art that the flavor and aroma of the tobacco product and the smoke from the tobacco are very important considerations in so far as the ultimate consumer is concerned. Considerable efforts are exerted by the manufacturers of tobacco products to provide a product that will be acceptable to the consumer, particularly as regards flavor and aroma characteristics. It has been the common practice in the tobacco industry to prepare blends of domestic and oriental tobaccos in order to provide smoking tobacco which has a pleasing flavor and aroma before and during smoking. However, such a procedure is costly and may at times become prohibitive in the event that certain types of tobacco may be in short supply. Accordingly, it is a further object of this invention to provide a new class of additive materials which when applied to the tobacco products improve and enhance the flavor and aroma of these products and the smoke emitted therefrom thereby increasing or enhancing the pleasure and other values that may be derived by the consumer from the use of these products.

A further object of this invention is the provision of a process for enhancing or otherwise improving the flavor, :aroma and other qualities of certain domestic, oriental, reconstituted or synthetic tobaccos which may be deficient in said flavor or aroma or other qualities.

An additional object of this invention is to provide a process of preparing a smoking tobacco or product which when smoked has an enhanced flavor or aroma.

An additional object of this invention is to provide a process of preparing a smoking tobacco or product which when smoked has an enhanced flavor or aroma.

A still further object of this invention is the provision of smoking products, such as cigarettes, cigars or pipe tobacco, and a process for forming same whereby the flavor and aroma before and during smoking are improved or enhanced.

Further and additional objects will appear from the following description and the appended claims.

In accordance with one embodiment of this invention, a tobacco product is provided to which has been added or which has been treated with a small amount of a compound selected from the group of compounds having the formula:

0 R1/\O/ Formula I wherein R R R and R are selected from the group consisting of hydrogen, alkyl and alkenyl radicals, with at least two of such substituents being an alkyl or alkenyl group and at least one of the latter groups being present in the gamma ring position. Preferably the alkyl or alkenyl radicals are those containing from 1 to 4 carbon atoms. The compounds falling within the scope of the generic Formula I are susbtituted gamma-lactones having at least two substituents selected from among alkyl and alkenyl radicals. Thus, preferably the R groups can be methyl, ethyl, ethylene, propyl, propylene, isopropyl, butyl, butylene and isobutyl.

The following specific examples illustrate the preparation and characteristics of representative tobacco additives of the present invention. It will be appreciated, however, that this invention is not limited to the specific processes by which the compounds may be prepared. All temperatures are expressed in degrees centigrade.

Example I.Synthesis of 4-hydr0xy-4-methyl-5- hexenoic acid, 'y-lactone In a 500 milliliter 3-necked flask, fitted with a thermometer, a Dry-Ice condenser, a dropping funnel and a magnetic stirrer, were placed 4.6 grams of magnesium, 175 milliliters of dry tetrahydrofuran and a drop of methyl iodide. The mixture was warmed to 45 as one milliliter of a solution of 23.1 grams of vinyl bromide in milliliters of tetrahydrofuran was added. Under vigorous stirring the reaction started and the temperature was maintained at 45-55 by the dropwise addition of the remaining vinyl bromide solution with periodic cooling. The reaction mixture was stirred at 45-55" an additional hour after all the vinyl bromide solution was added.

To the vinyl magnesium bromide solution was added 10 grams of levulinic acid in 50 milliliters of tetrahydrofuran keeping the temperature at 7l5'. After the addition of the levulinic acid solution the reaction mixture was allowed to come to room temperature and stirred an additional two hours. The solvent was removed under reduced pressure; 250 milliliters of water was carefully added followed by milliliters of 10% acetic acid. The mixture was extracted with ether, the ether extract dried over sodium sulfate and concentrated. The residue was distilled in vacuo yielding two grams of 4-hydroxy-4- methyl-S-hexenoic acid, -lactone, boiling point 65- 67/ 2 mm. This material has the formula CHz==CH 0 Example 11 C2H5 Example IlI.- 8,' -Dimezhyl-y-butymlacmne (a) fi-meihyllevulinic acid.-To a refluxing solution of 57.6 grams of ethyl-wmethylacetoacetate in 400 milliliters of benzene was added 0.4 mole of potassium hydroxide pellets in small portions over a two-hour period. Water (7 milliliters) was removed azeotropically, and 44.2 milliliters of ethylbromoacetate was added to the solution under reflux. After five more hours of refluxing, the benzene was removed by distillation and water was added to the solution. The organic layer was separated and the aqueous layer was extracted several times with ether. The ether extracts were combined with the organic layer and concentrated. The residue was distilled in vacuo, yielding 19 grams of fi-methyllevulinic acid, boiling point 97l03/l mm.

(b) By-dimethyl-' -buzyrolaataaa-To a solution of 8 grams of B-methyllevulinic acid in ethanol-water was slowly added 12.7 grams of potassium borohydride over a two-hour period. After stirring for one-half hour, the reaction mixture was acidified with 30% hydrochloric acid and extracted several times with ether. The combined ether layers were washed with water (to remove the boric acid), dried, concentrated, and distilled; yield 5.2 grams of ,e -dimethyl-y-butyrolactone, boiling point 61-63/l mm. having the formula:

CH CHQAL J20 Each diastereoisomer and its enantiomer are considered within the scope of the invention.

(a) ot-methyllevulinic acid.-To a solution of 11.5 grams of sodium in 250 milliliters of anhydrous ethanol, 65 grams of ethylacetoacetate was added with stirring. To this clear solution of sodio-ethylacetoacetate 91 grams of ethyl 2-bromopropionate was added and the mixture brought to reflux for 12 hours. This ester product was directly hydrolyzed with sodium hydroxide solution followed by careful acidification with 1: 1 sulfuric acid. The organic material was extracted from this reaction mixture with ether and worked up in the usual manner to furnish 68 grams of yellow residual oil. Distillation of this oil at '1 mm. pressure furnished 50.15 grams of pure u-methyllevulinic acid, collected at B.P. 114117.

(b) otq-dimethyl- -butyrolactone.Thirteen grams of tx-methyllevulinic acid was dissolved in 30 milliliters of Water containing 4 grams of sodium hydroxide and then diluted with 30 milliliters of methanol. This solution was then added to a stirred solution of 1.5 grams of sodium borohydride in 30 milliliters of methanol and stirred at room temperature for 1.5 hours, after which it was hydrolyzed with 10% hydrochloric acid. The lactone was extracted with ether and worked up in the usual procedure to provide 8 grams of crude a,'y-dimethyl-'y-butyrolacetone. Distillation through a 30 cm. column of Podbelniak helices provided a mixture of the two diastereomers, B.P. 3435/.7 mm.

It has been found that the tobacco additives of the invention when incorporated into tobacco products impart a flavor and aroma both before and during smoking which many smokers consider to be desirable in smoking products. However, it is pointed out that the methods for defining or characterizing the quality of a flavor or aroma in the tobacco art are almost purely subjective and different smokers may define the same flavor quite differently. Also, the compounds included within the broad scope of this invention may impart different flavors or aromas depending upon the alkyl substituents therein. Thus, the compounds comprehended by this invention, by subjective tests, impart characteristic flavors which are desirable in tobacco products and the smoke therefrom even though the exact character thereof cannot be described on the basis of known standards. The tobacco additive of Example I imparts an aroma or flavor which is reminiscent of peppermint which many smokers consider to be desirable in a tobacco product. The tobacco additive of Example 11 imparts an aroma and flavor which some characterize as peppermint nut-like; the tobacco additive of Example III a sweet aroma; and that of Example IV a sweet, spicy-coconut flavor and aroma.

In accordance with this invention, a compound embraced by generic formula I or mixtures thereof is added to tobacco or applied to a smoking article or its component parts in amounts of about 0.005 to 1.0 percent by weight of the product. Preferably the amount of additive is between about 0.05 and 0.5 percent by weight in order to provide a tobacco product having a desired flavor and aroma. However, the amount used will depend upon the amount of flavor and aroma desired and the particular compound or mixture thereof that is used. The additive may be incorporated at any step in the treatment of the tobacco but is preferably added after aging, curing and shredding and before the tobacco is formed into cigarettes. Likewise, it will be apparent that only a portion of the tobacco need be treated and the thus treated tobacco may be blended with other tobaccos before the cigarettes or other smoking articles are formed. In such case the tobacco treated may have the additive in excess of the amounts above indicated so that when blended with other tobaccos the final product will have the percentage within the indicated range.

In accordance with one specific embodiment of this invention, an aged, flue-cured and shredded tobacco is sprayed with a 1% ethyl alcohol solution of 4-hydroxy- 4-methyl-5-hexenoic acid, a-lactone in an amount to provide a tobacco containing 0.05 percent by weight of the additive on a dry basis. Thereafter the alcohol is removed by evaporation and the tobacco is manufactured into cigarettes by the usual techniques. It has been found that the cigarette when prepared as indicated has a desired and pleasing flavor, an aroma which to some people is reminiscent of peppermint and is detectable and pleasing in the main and side smoke streams when the cigarette is smoked.

The additives falling within the scope of this invention may be applied to the tobacco by spraying, dipping or otherwise, utilizing suitable suspensions or solutions of the additive. Thus water or volatile organic solvents, such as alcohol, ether, acetone, volatile hydrocarbons and the like, may be used as the carrying medium for the additive While it is being applied to the tobacco. Also, other flavorand aroma-producing additives, such as those disclosed in United States Patents Nos. 2,766,145, 2,905,575, 2,905,576, 2,978,365 and 3,041,211 may be incorporated into the tobacco with the additive of this invention.

While this invention is principally useful in the manufacture of cigarette tobacco, it is also suitable for use in connection with the manufacture of pipe tobacco, cigars or other tobacco products. Furthermore, the compounds may be added to certain tobacco substitutes of natural or synthetic origin and by the term tobacco as used throughout this specification is meant any composition intended for human consumption by smoking or otherwise, whether composed of tobacco plant parts or substitute materials or both.

Also, the invention has been particularly described with reference to the addition of the compounds directly to tobacco. However, it will be apparent that the compound may be applied to the paper of the cigarette or to the wrapper of a cigar. Also it may be incorporated into the filter tip, the packaging material or the seam past employed for gluing the cigarette paper. Thus a tobacco product is provided which includes the specified additives and tobacco although in every instance the compound need not be admixed with the tobacco as above specifically described.

While several particular embodiments of this invention are shown above, it will be understood, of course, that the invention is not to be limited thereto, since many modifications may be made, and it is contemplated, therefore, by the appended claims, to cover any such modifications as fall within the true spirit and scope of this invention.

We claim:

1. A tobacco product having added thereto an amount suflicient to alter the flavor or aroma of the tobacco prodnet of a compound selected from the group of compounds having the formula net of a compound selected from the group of compounds having the formula R1 0 Formula I wherein R R R and R are selected from the group consisting of hydrogen, alkyl and alkenyl groups of from 1 to 4 carbon atoms with at least two of such substituents being other than hydrogen and at least one of the latter groups being present in the gamma ring position.

3. The product recited in claim 1 wherein the amount of said compound is between about 0.005 and 1.0 percent by weight of the product.

4. The product recited in claim 1 wherein the amount of said compound is between about 0.05 and 0.5 percent by weight of the product.

5. A tobacco product having added thereto and dispersed therein a small amount suflicient to improve the flavor thereof of 4-hydroxy-4-methyl-S-hexenoic acid, 7- lactone.

6. A tobacco product having added thereto and dispersed therein a small amount sufficient to improve the flavor thereof of 4-hydroxy-4-m'ethylhexanoic acid, 7- lactone.

7. A tobacco product having added thereto and dispersed therein a small amount sufficient to improve the flavor thereof of flyy-dimethylq-butyrolactone.

8. A tobacco product having added thereto and dispersed therein a small amount suflicient to improve the flavor thereof of ugy-dimethyl-v-butyrolactone.

9. The product recited in claim 5 wherein the amount of flavorant is between about 0.005 and 1.0 percent by weight of said tobacco.

10. The product recited in claim 6 wherein the amount of flavorant is between about 0.005 and 1.0 percent by weight of said product.

11. The product recited in claim 7 wherein the amount of flavorant is between about 0.005 and 1.0 percent by weight of said product.

12. The product recited in claim 8 wherein the amount Y of flavorant is between about 0.005 and 1.0 percent by weight of said product.

13. A process for improving the flavor of a tobacco product which comprises adding thereto a small amount of a compound selected from the group of compounds having the formula aR I I 0 R \O wherein R R R and R are selected from the group consisting of hydrogen, alkyl and alkenyl groups with at least two of such substituents being other than hydrogen and 'at least one of the latter groups being present in the gamma ring position.

14. A process for improving the fllavor of a tobacco product which comprises adding thereto a small amount of a compound selected from the group of compounds having the formula wherein R R R and R are selected from the group consisting of hydrogen, alkyl and alkenyl groups of from 1 to 4 carbon atoms with at least two of such substituents being other than hydrogen and at least one of the latter groups being present in the gamma ring position.

15. The process of claim 13 wherein the compound is added in an amount from about 0.005 to 1.0 percent by weight of the product.

References Cited UNITED STATES PATENTS 2,766,147 10/1956 Rowland 13117 2,872,360 2/ 1959 Teague 131264 X SAMUEL KOREN, Primary Examiner. MELVIN D. REIN, Examiner. 

1. A TOBACCO PRODUCT HAVING ADDED THERETO AN AMOUNT SUFFICIENT TO ALTER THE FLAVOR OR AROMA OF THE TOBACCO PRODUCT OF A COMPOUND SELECTED FROM THE GROUP OF COMPOUNDS HAVING THE FORMULA 